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Question

Below are given two sets of numbers. In each set of numbers, certain mathematical operation(s) on the first number result(s) in the second number. Similarly, certain mathematical operation(s) on the second number result(s) in the third number and so on. Which of the given options follows the same set of operations as in the given sets?

(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13 such as adding to/subtracting from/multiplying with 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)

10 - 100 - 50 - 25; 2 - 4 - 2 - 1

This question was previously asked in
RRB ALP 2025 CBT 2 Wiremen Question Paper (28-Jul-2026) (Shift 2)
The correct answer is

4 - 16 - 8 - 4

To solve this problem, we need to identify the pattern in the given sequences and then apply the same pattern to the options to find the correct one that matches.

Let's examine each set of numbers and the operations performed on them:

  1. Sequence 1: 10 - 100 - 50 - 25
    • The operation from 10 to 100 is multiplication by 10: \(10 \times 10 = 100\)
    • The operation from 100 to 50 is division by 2: \(100 \div 2 = 50\)
    • The operation from 50 to 25 is again division by 2: \(50 \div 2 = 25\)
  2. Sequence 2: 2 - 4 - 2 - 1
    • The operation from 2 to 4 is multiplication by 2: \(2 \times 2 = 4\)
    • The operation from 4 to 2 is division by 2: \(4 \div 2 = 2\)
    • The operation from 2 to 1 is again division by 2: \(2 \div 2 = 1\)

From these observations, the pattern consists of the following operations:

  1. Multiply the first number by 2 (or 10 in the first sequence for an increment operation)
  2. Divide by 2
  3. Divide by 2 again

Now, we will apply these operations to the options provided and find which option matches the pattern:

  1. Option 1: 12 - 144 - 62 - 31
    • 12 to 144: \(12 \times 12 = 144\) (doesn't match the pattern as it exceeds the multiplication factor)
    • 144 to 62: No clear pattern (involving unexpected results)
  2. Option 2: 5 - 25 - 15 - 7
    • 5 to 25: \(5 \times 5 = 25\) (does not match the required multiplication factor)
  3. Option 3: 4 - 16 - 8 - 4
    • 4 to 16: \(4 \times 4 = 16\) (matches the multiplication by factor = 4)
    • 16 to 8: \(16 \div 2 = 8\) (matches division by factor = 2)
    • 8 to 4: \(8 \div 2 = 4\) (matches division by factor = 2)
  4. Option 4: 8 - 64 - 32 - 14
    • 8 to 64: \(8 \times 8 = 64\) (doesn't match as per given pattern)

Therefore, the option 4 - 16 - 8 - 4 matches the defined operations for the given number sequences. Thus, the correct answer is:

Option 3: 4 - 16 - 8 - 4

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Similar Questions

  1. Select the set that does NOT belong in the following group of sets.

    (2, 14, 16), (6, 30, 36), (5, 35, 40), (3, 21, 24)
  2. Two sets of numbers are given below. In each set of numbers, certain mathematical operation(s) on the first number results in the second number. Similarly, certain mathematical operation(s) on the second number results in the third number and so on. Which of the given options follows the same set of operations as in the given sets? (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into their constituent digits. E.g. 13 – Operations on 13 such as adding/subtracting/multiplying to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.) 68 – 136 – 121 – 363; 29 – 58 – 43 – 129
  3. If 2 is added to each odd digit and 1 is subtracted from each even digit in the number 2741586, how many digits will appear more than once in the new number thus formed?
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    The set that does NOT belong to the group is:

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Important Questions from Number Based

  1. In the following question, four number pairs are given. The number on left side of (-) is related to the number of the right side of (-) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

  2. Select the set in which the numbers are related in the same way as are the number of the following set.

    (3, 7, 58)

  3. Find the odd number/letters from the given alternatives.

  4. Find the odd number/letters from the given alternatives.

  5. Identify the number which is different from the other.

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